Hi @Westerwald_Rider "So that the navigation instructions can be heard clearly above the music."
I suspect if you have NO music playing, the MRA audio volume will be plenty loud enough to hear clearly, this is easy to test
IF the volume is loud enough with NO music then what I think the issue about MRA being quiet WITH music is because the user sets the volume level that they want the music to be comfortable at
What is not realised is that a lot of music player apps boost the volume so that they can be produce very high volumes,
quiet or even medium volume rock & roll is just NOT rock & roll
If you set the volume for comfortable music then MRA will sound quieter in comparison because it is not boosted
I learned this because I had the same issue, quiet MRA voice instructions
My fix has been to use a music app with equalizer or Replay gain settings so that I can control/reduce the music app volume output so it is un-boosted & matches the normal volume output of other apps such as MRA
With the music app & mra set to the same output levels then both increase equally using the phone volume controls
Thats was the case for me, it was not MRA's fault but mine for using a loud music app that drowned out the MRA app, other cases may be different especially using carpuride/android auto